Various types of sink units of the character described have been proposed, and particularly sink units which have two main compartments, one forming a washing or main working sink, the other a rinsing sink or a zone for a drain board; alternatively, a rinsing sink may be provided with a drain board cover slidable thereover, for example to support a dish drainer or the like. Such sinks usually have a splash guard or water retention rim, which is raised above the upper edge of the respective sinks or drain board, to prevent spilled water from running over the edge and, for example, dripping on the floor.
The third division of the sink unit as a whole, which may be a further sink or a drain board or a sink with a drain board fitted thereover, for selective use as a sink or drain board will, hereinafter in the specification and claims, be referred to as a "water receiving zone or region"--unless otherwise described, since, selectively and according to demand of the customer, a solid drain board, a removable drain board or a sink may be installed in that zone or region, each one of them, however, having the function of reception of water.
Sinks of the type described have been provided by the assignee of the present application and sold under the terms "Compact" and "Compact Soft", respectively. The narrower or cleaning sink unit is located centrally between the main wash sink and the water receiving region. A raised region is located in front as well as behind the washing and cleaning sink unit. One of those regions may be constructed with suitable openings to receive a spout and valve, and the associated control handle or handles of a faucet assembly.
Other types of sinks have been proposed in which a very narrow cleaning sink unit is provided functioning, essentially, only as a drain for waste or garbage products, so that it can hardly be used for any purpose other than disposal of liquid waste and the like, e.g. coffee grinds, rinse water from bottles, etc. (see the referenced French Publication "Technique & architecture", and German Patent Disclosure Document DE-OS No. 25 00 337).
The sinks so far described have one advantage: They provide for hygienic separation of various working regions: A washing sink unit and a drying or dripping region or zone, which are so arranged that water dripping off the drying or dripping zone will not drip into the washing sink unit. If the drying or dripping zone or region is used for cleaning, water running off the zone will not run into the main washing sink unit to contaminate water therein or other articles therein; conversely, water which might run over from the main sink unit cannot reach over into the water receiving zone to soak or at least partially immerse or otherwise contaminate dishes which might already have been washed and are stacked there, for example for drying.
The separation of the working regions is completed by providing a separate drain for the water receiving zone. The main sink unit is formed with the customary overflow opening or drain therefrom, at a high elevation with respect to the bottom of the sink unit, which, also, provides for venting to prevent possible syphoning action, if the sink is installed in a multi-story apartment building, for example. The separate drain, and the overflow--which is required by some governmental building and sanitary codes--insure that water from the water receiving zone can reach the central working or drainage region or unit; likewise, water which might rise in the main sink unit--for example due to inadvertent failure to shut off a water supply spout--cannot overflow into the central sink unit. This is particularly important if, for example, the central sink unit has been filled with clear, clean water, for example in order to rinse glasses, already washed in the main sink unit.
Sink units as described, although having numerous advantages, are comparatively expensive and, further, require comparatively expensive installation, since four drain and/or vent connections must be formed on the sink unit and, thereafter, connected.